1. Field of the Invention
The invention relates to watertight connector and to a method for assembling the connector.
2. Description of the Related Art
A watertight connector is disclosed in Japanese Unexamined Patent Publication No. 6-203902 and is shown in FIG. 17 herein. The connector has a male housing 1 with cavities 2. A one-piece rubber plug 3 is provided at the rear side of the male housing 1 and is formed with wire insertion holes 4 at positions corresponding to the cavities 2. A plug holder 5 presses the rubber plug 3 forward and has terminal insertion openings 6 at positions corresponding to the wire insertion holes 4. Male terminal fittings 7 are fastened to ends of wires W and are inserted through the corresponding terminal insertion openings 6 of the plug holder 5. The terminal fittings 7 penetrate the rubber plug 3 by resiliently widening the wire insertion holes 4 and then advance into the cavities 2. The inner surfaces of the wire insertion holes 4 resiliently return toward their original shape after passage of the male terminal fittings 7 to achieve close sealing contact with the outer surfaces of the wires W.
The male terminal fitting 7 may be inserted obliquely, as shown at an upper stage of FIG. 17. Thus, a tab 8 at the leading end may strike against the inner surface of the wire insertion hole 4 of the rubber plug 3, and may deform or damage the rubber plug 3.
Damage to the rubber plug 3 could be avoided by thickening the plug holder 5 and elongating the terminal insertion openings 6. Thus, the orientation of the male terminal fitting 7 can be corrected while passing through the long terminal insertion opening 6, even if the male terminal fitting 7 initially is inserted obliquely. However, the thicker rubber plug holder 5 leads to a longer connector. This problem also is seen in male watertight connectors.
The present invention was developed in view of the above problem and an object thereof is to enable terminal fittings to be inserted in a proper orientation without enlarging a connector.
The invention is directed to a watertight connector with a housing that has at least one cavity. At least one terminal fitting is fastened to the end of a wire and is accommodated in the cavity. A sealing plug is mounted at a first surface of the connector housing and is formed with wire insertion holes at positions substantially corresponding to the respective cavities. The wire insertion holes are dimensioned to closely contact the outer surfaces of the wires. A plug holder is mounted on the housing and has terminal insertion openings at positions substantially corresponding to the wire insertion holes.
Thus, the terminal fittings are insertable through the terminal insertion openings. The plug holder can be held at a partial locking position where the plug holder is spaced from the sealing plug and at a full locking position where the plug holder presses the sealing plug. The terminal fittings are insertable toward the cavities through the terminal insertion openings when the plug holder is at the partial locking position. The plug holder may be moved to the full locking position after the terminals are inserted into the cavities.
The terminal fittings are inserted when the plug holder is at the partial locking position spaced back from the sealing plug. Thus, the leading ends of the terminal fittings are guided into the proper orientation by the inner surfaces of the terminal insertion opening before reaching the sealing plug, even if the terminal fittings are inserted obliquely into the terminal insertion openings. As a result, the leading ends of the terminal fittings will not collide with the inner surfaces of the wire insertion holes of the sealing plug, thereby preventing both deformation of the terminal fittings and damage to the rubber plug.
The rubber plug holder is pushed to the full locking position after the terminal fittings have been inserted. Thus, the connector can be compact and can have a small depth when in use.
The plug holder is at the partial locking position when the leading ends of the terminal fittings reach the entrances of the wire insertion holes of the sealing plug. Thus, the inclination of the terminal fittings is suppressed to or below an angle of inclination where the leading ends of the terminal fittings contact slanted guide surfaces at the entrances of the wire insertion holes.
The terminal fitting may remain inclined due to a fitting tolerance between the terminal fitting and the terminal insertion opening. However, the maximum inclination is suppressed sufficiently for the leading end of the terminal fitting to contact the guiding surface at the entrance of the wire insertion hole. Thus, even if an inclination remains, the terminal fitting is inserted into the wire insertion hole with an orientation corrected substantially to the proper orientation by the guiding surface and by the forwardly directed pushing forces on the terminal fitting.
A loose movement restricting means may be provided in the housing and/or on the plug holder. The loose movement restricting means restricts a loose movement of the plug holder in directions at an angle to an inserting direction of the terminal fittings, when the plug holder is at the partial locking position. Thus, the plug holder corrects the orientation of the terminal fittings more effectively.
The loose movement restricting means may comprise an engaging hole in the housing and an engaging pin that projects forward on the holder. Loose movement of the plug holder is restricted by the insertion of the engaging pin into the engaging hole when the plug holder is at the partial locking position.
The plug holder preferably is molded of a synthetic resin, and at least one thinning recess is formed by partly cutting away an area of the outer surface of the engaging pin that is inserted in the engaging hole when the plug holder is at the partial locking position. Thus, there is no possibility of deforming the engaging pin due to xe2x80x9csink marksxe2x80x9d during the molding of the plug holder. Accordingly, undesirable shaking between the engaging pin and the engaging hole due to deformation of the engaging pin can be avoided, and the function of correcting the orientation of the terminal fittings will not be impaired.
The plug holder is molded by a mold that opens in a direction substantially parallel with a projecting direction of the engaging pin. Additionally, the thinning recess is a groove that extends oblique to the projecting direction of the engaging pin. Thus, the engaging pin is easily separable from the mold when the mold is opened in a direction parallel with the projecting direction of the engaging pin.
The plug holder preferably is molded of a synthetic resin, and a sealing surface is formed on an area of the outer surface of the engaging pin that closely contacts the inner surface of the insertion hole of the sealing plug when the plug holder is at the full locking position. Additionally, a thinning hole is formed by cutting away an inner portion of the engaging pin corresponding to the sealing surface. Thus, there is no possibility of deforming the engaging pin with xe2x80x9csink marksxe2x80x9d created during the molding of the plug holder. Accordingly, adhesion between the sealing surface and the insertion hole of the rubber plug is not reduced due to the deformation of the engaging pin, and the sealing function is not impaired.
The invention also relates to a method for assembling a watertight connector. The method comprises providing a housing with at least one cavity for receiving a terminal fitting fastened to an end of a wire. The method also includes mounting a sealing plug at a first surface of the housing. The sealing plug is formed with at least one wire insertion hole substantially aligned with the cavity. The method then includes mounting a plug holder to the housing at a partial locking position spaced from the sealing plug. The plug holder has at least one terminal insertion opening aligned with the wire insertion hole. The method continues by inserting the terminal fitting through the terminal insertion opening and into the cavity, and then moving the plug holder to a full locking position pressed against the sealing plug.
These and other objects, features and advantages of the present invention will become more apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are described separately, single features thereof may be combined to additional embodiments.